The formation of marble results from the metamorphosis of sedimentary carbonate rocks like limestone or dolomite undergoing variable recrystallization.
When all that epic geological stuff happens, you end up with a beautiful and durable structure composed of interlocking carbonate crystals. The pure white version of marble arises from components like exceptionally pure limestone or dolomite. The swirls and vein-like structures in colored marbles come from the inclusion of impurities like clays, sands or iron oxides present in the original limestone formations. Those impurities are then recrystallized by intense pressure and heat generated beneath the surface of the earth.
Marble has been the material of choice for artists intent on capturing forms made to last beyond a lifetime, indeed, to make an attempt to transcend time itself. The impenetrable and cool surface of wrought marble captured images like Discobolus, The Dying Gaul, Praxiteles' Hermes and the Infant Dionysus and Michelangelo's Pieta and David.
For centuries artists have been crafting marble for use in architecture and art, and for all those years, marble quarries have generated waste materials which produce unhealthy levels of calcium carbonate fallout in the surrounding landscape.
Now a group of Italian engineers from MarbleEcoDesign are binding that marble dust with a photo-reactive polymer to create a marble material suitable for 3D printing applications.
"Sludge and waste are a consequence of the (marble) production system," said Project Leader Michela Ruggiero. "Marble dust is complex and expensive to dispose of, but if mixed with special resins and catalyzed with UV rays, these substances can be transformed into raw material ideal for 3D printing."
As part of their partnership with Design Lab Frosinone, MarbleEcoDesign has made a fused filament fabrication 3D printer capable of creating parts with step resolutions as fine as ~0.5 μm. Their machine, which features an extruder boasting a 0.15 mm steel nozzle, produces 0.16 mm droplets.
Begun near the marble quarries of Coreno Ausonio, in southern Lazio, Italy, the MarbleEcoDesign process mixes resins with the marble dust which are then catalyzed with UV rays to harden.